Hi Colin!
First at all do the following steps:
* Thoroughly (but carefully) clean all connectors,
* Make sure that all connectors (on the motherboard side and on screen flex side) aren’t broken or crooked
* Make sure that you plugged connectors correct (as in [guide|113862|Screen replacement guide])
Did you connected screen or battery as first?
If that steps won’t help, in 90% your new screen is damaged. Try to contact with customer support.